XML/EDIFACT is an Electronic Data Interchange (EDI) format used in Business-to-business transactions. It allows EDIFACT message types to be used by XML systems.
EDIFACT is a formal, readable language-for-machine description of electronic business documents. It uses a syntax close to delimiter separated files. This syntax was invented in the 1980s to keep files as small as possible. Because of the Internet boom around 2000, XML started to become the most widely supported file syntax. But for example, an invoice is still an invoice, containing information about buyer, seller, product, due amount. EDIFACT works perfectly from the content viewpoint, but many software systems struggle to handle its syntax. So combining EDIFACT vocabulary and grammar with XML syntax makes XML/EDIFACT.
The rules for XML/EDIFACT are defined by ISO TS 20625.